Rep. Jerrold Nadler, a longtime ally of Israel whose Brooklyn-Manhattan district includes the largest number of Jewish voters in the United States, announced Friday that he’s supporting the Iran nuclear deal.

“I have concluded that, of all the alternatives, approval of the JCPOA, for all its flaws, gives us the best chance of stopping Iran from developing a nuclear weapon,” he said, referring to the pact’s official name, the Joint Comprehensive Plan of Action.

The announcement drew anger in his district, where some accused Nadler, a Democrat, of kowtowing to President Obama.

“I don’t trust politicians. They’re all hoping to get a favor from Obama. It’s a terrible deal,” said Borough Park business owner Judy Gutnam.

“Aren’t they [Iran] the ones that kept Americans hostage? It’s a real betrayal of the American people.”

Bobby Grazioso, 48, a consultant in Bensonhurst, blasted the deal.

“They’ve broken all the rules. They want to destroy Israel. They they don’t like the American people. They blatantly said it,” he said.

Assemblyman Dov Hikind (D-Borough Park) said he was “extremely disappointed” with Nadler and called him “persona non grata.”

In backing the deal, Nadler is bucking Sen. Charles Schumer, who opposes it.

Nadler released a letter from Obama that he said addressed his concerns.

“Although we know that Iran will remain a major menace to the region and the world, even without nuclear weapons, a nuclear-armed Iran would represent an unacceptable threat to the United States, to Israel and to global security,” Nadler said.

“With respect to this objective, the interests of the United States and of Israel are identical, even as there are different views on how to achieve it.”

“The only decision that matters at this moment is whether to support or reject the agreement that is on the table now,” he said.